Caoutchouc derivative and process of making the same



lemma 1.... 3, 1928.

UNITED "STATES 1,654,844 PATENT OFFICE.

HERMANN STAUDINGER, OF FREIBULRG, BADEN, GERMAN Y, A SSIGNOR TO THE FIRM SOCIETY OF CHEMICAL INDUSTRY IN BASLE, OF BASEL, SWITZERLAND.

CAOUTGHOU-C DERIVATIVE AND PROCESS OF MAKING THE SAME.

No Drawing. Application filed December 22, 1926, Serial No. 156,530, and in Switzerland December 31,

part of its double linkings, passes into a' oyclo'caoutchouc, which has physical atnd chemical properties differing from those of ordinary caoutchouc. This cyclocaoutchouc can be obtained in the form of a solid amorphous powder, or of flocks, which have the appearance of gutta-percha. It is not fully saturated but contains for fl to 5 isoprene residues one double linking, so that it reacts with oxidizing agents, for instance concentrated nitric acid.

pressure; there may also be present an ind fferent solvent, such as benzlnes, particularly paraffin hydrocarbons and cyclopara-ffin hydrocarbons. V 1 I In order to obtain such hydro-cyclo caoutchouc another mode ofoperating is first of an indifferent solvent, to 200250 G. and

to heat caoutchouc, preferably with addition thereby convert it into the cyclic compound;

this operation maybe accelerated by addition of an acid, such as acetic acid. The" catalyst is then added and the cyclo-caoutchouc hydrogenized under hydrogen pressure.

Yet another procedure is to mix caoutchouc with a SlOWly'acting catalyst, such as copper der hy rogen pressure tov about 250270 C.

The formation of .the cycle-compound first.

occurs and this compound is only gradually reduced to the hydro-cyclocaoutchouc.

The hydro-eyclocaoutchpuc obtained by I one or other of the foregoing procedures is a solid, white, amorphous mass, soluble in benzene, chloroform or ether; it is not soluble in alcohol or acetone and therefore can be purified by dissolving it in the first named solventsand precipitating it by addiwder, and to heat. the mixture untion of alcohol or acetone. from the hydrocaoutchouc previously described (Staudinger and Fritschi, Helv. v. 785) in that it is solid, Whereas-the previously known hydrp-caoutchouc is a tough highly viscous mass. In common to both these'c'aoutchouc derivatives is their chem ical indifference. They can further be distinguished easily with aid of the refractometer, since pure hydrocaoutchouc has the refractive index n-% 1.4=770, whereas pure hydro-cyclocaoutchouc has the refractive in dex n =L5263. The specific gravity of hydro-cyclocaoutchouc is greater than that of hydrocaoutchoucL chouc is useful for the manufacture of plastic masses andas a substitute for guttapercha.

The following examples illustrate the invention:'-

Example J.'-Cyclocaoutchouc is triturated with finely subdivided platinum or nickel, and then heated in a rotary autoclave under -80 atmospheres pressure of hydrogen for 2030 hours to 270? C. After cooling, the 'mass is extracted with benzene, the extract filtered from the catalyst and the hydro-cyclocaoutchouc obtained either by distilling away the benzene with steam or by ordinary distillation, or the hydro-cycloalcohol to the benzene extract.

Ewample 2. Caoutchouc is. heated in a so ed-finely subdivided nickel carried on pumice and the mixture is heated under hydro-. gen pressure in a rotary autoclave for 6 hours at290 C. The hy-dro-cyclocaoutchouc isworked up. as in the preceding example. Ewa/r'nple 3. Caoutchouc is mixed with copper oxide carried on pumice and tlie mixture is heated under hydrogen pressure in an autoclave having a stirring device for 4 hours.v The solid hydro-cyclo caoutchouc thus obtained is worked up in the manner described in the'first example.

What I, claim is:

n is different The hydro-cyclocaoutcaoutchouc may be precipitated by adding 1. A process for the manufacture'of hyi dro-cyclocaoutchouc by reducing oyc'locaoutchouc in presence of a catalyst by means of hydrogen.

2. A process for the manufacture of hydro-cyclocaoutchouc by reducing cyclocaoutchouc in presence of a catalyst by means of hydrogen under pressure.

3. A process for the manufacture of hydro-cyc'locaoutchouc by reducin chouc in presence of'a cataIystiJy meansof hydrogen at temperatures above 200 C.

4. A process for the manufacture of hydro-cyclocaoutchouc by reducing cyclocaoutchouc in presence of a catalyst by means of hydrogen under pressure and at temperatures above 200 C.

5. A process for the manufacture of hy-' dro-cyclocaoutchouc by reducing cycl'ocaoutchouc in presence of a metal of the 8th series of the periodic system by means of hydrogen.

' 6. A process for the manufacture of hydro-cyclocaoutchouc by reducing cyclocaoutchouc in presenceof a metal of the 8th secyclocaout ries of the periodic system by means of hydrogen under pressure.

7. A process for the manufacture of hydro-cyclocaoutchouc by reducing cyclocaoutchouc in presence of a'metal of the 8th series of the periodic system by means of hydrogen at temperatures above 200 C.

8. A'process for the manufacture of hydro-cyclocaoutchouc by reducin cyclocaoutchouc in presence .of a metal 0?, the 8th series of the periodic system by means of hy drogen under pressureand at temperatures about 200C.

9. As new article of manufacture hydrocyclocaoutchouc representin a solid, white, amorphous mass, soluble in enzene, chloroform or ether, insoluble in alcohol and acetone, having the refraction index 1 .5263. I

In witness whereof I have hereunto signed my name this 11th day vof December, 1926.

HERMANN STAUDINGER. 

